Governing mechanism for mixed-pressure turbines.



F. -SAMUELSON GOVBBNING MECHANIBM FOB MIXED PRESSURE .TURBINES.APPLIUATIGF FILED IAB. 16, 1910.

973,705. l Pantea ot.25,191o.

2 BKEETHHEET 2.

; u l:V Y W n VM*- Figs.

go; Inventor-z F'redercKSamuelsorl b9 /ZMQM fUNiTEDsTATEs PATENT OFFICE.

FREDERICK SAMU-ELSON, OF RUGBY.- ENGLAND, ASSIGNOR T0 GENERALELEC'JIRICl COMPANY.' A CORPORATION OF NEW YORK..

GOVERNING MEOHANISM FOR MIXED-PRESSURE TURBINES.

To. all whom t may concern: A

Be it known that-I. FiucunlneleSurfin.- S'ON, 4a vsubject of the King ofSweden, residing at Rugby. England` have invented certa-in. new anduseful Improvements in. Governing'-Mechanisms for Mixed-PressureTurbines. of which the followingis a .specification.

The presentinventionrelates to governing mechanisms for minted pressuretur! b1nes, and-has for its object tOv nnprove their constructionwhereby. th'e57 are ren- .de1ed more certain -and reliable in Opera--'-tlontjboth under normal and einerg'encjY conditions,

For a consideration of'what I conslder to 'b e novel .and my'-invention. attention is. di

rented -to the accompanying descriptions 4A.and claims appended hereto.

lIn tlie acco 1npanyin'g drawings. which illustrate one-ofthe-'embodiments Of-my in'- vention'jf F igure "1 is an e-nd'view of atur- `bine -Sh'oi'vixng, certain "of the valve parts in section-[Fig.and-'theeam sh-af-tfor .actuating the high l,pressurex1ozzle val ves:Fig. 3 is a detailed viewshowing the pllot valve-for' controllingrtheadinissiom of motive fluid to the motorl that. act'uates'thecani-shaft; Figjiis a de' `which i s"indic@ated at 12.'

tailed v-ieW showing a'part of the follow-up- .devicei Fi-gs. 5.and'0are detailed views of the locking lever 'o t"4 the butterfly valve: Fig.Tis across section ofthetmotor that tnatefsi .the-camshaft., and Fig.' Sade- .tailedve-.w vof the emergency governor'.

10. indicates" the base of the machiue. vand mounted thereon is' a.turbinerasing 11. which contains as; vmany .rows of wheel` bueket's 'or'vanesand as 1nany,nozzles or Huid dischnrgingdevlces as are'i'iecessarytoV extractthe energv from the steam'or 'ed .onV a suitable shaft.. lthereduced end, of This shaft ,is ymountedfin bearings 13,0111)Y one ofwhich is. shown tgures.

twoindependent sources o f, the fluidl sup ply.

v'High pressulfesstealn is, admitted by thecon-l duit ll'tothehighpxessure-va-lve'chest 15.

- Low pressuie'steam 'lis' 4admitted tothe tur-1 bine byfthe conduiig*that communicates' Specification of Letters Patent.

Application filed March 1(1'` on account of the character Of the Steam,is admitted to `tlie turbine 'front utented Ovt. 55,

1910. Serial No. 549,747.

with the low pressure valve chest 1T. Steam for the high pressureservice muv be received. from a boiler or other suitable source. and thesteam for low' pressure niav be received from the exhaust ot'- areciprocating engine or from an aceunmlator. or any other'suitablesource. As arrangedthe high pressure steam passes throughnozzles or directing devices that are separated from the nozzles lordirecting devices through .which the low'pressure steam passes.` Owingto the diference'in the volume ofthe high and low lin'essnre steam, thenoz'zles for the latter-must have. -a greater cross see-- tional area inOrder to' convey it.

One speed governor is employed'for eontrolling the admission of steamfrom both high and low pressure sources. By reason of this arrangementthe apparatus is simplified and the proper sequence of operation of thevarious valves can be insured.' This governor. which mavbe of anysuitable type.

comprises in the present instance. weightsv y,reasoi'i'that.it seemsunnecessary to' a proper -understandln-gA of' 'my invention.

The speed governor-is provided with -a collar-.Q0 that moves up and.down as the weights move in and out. This collar-actuates the governorlever 2l that is pivoted toa suitable support." To the opposite endtains the adjustable coupling Q53 whereby -the length of the rod-can beadjusted. The

upper end ofthe rod is connected to the lever 2J: that actuates thepilot. 'valve'. ,-'The latter is moi-ei partieularh1 shown' inv yFig.

"of the lever is connected a rod 252. which conf' This pilot valvecontrols the adltnission of motive- Huid. (which may be "liquid forelastic fluid under pressure) `tothe -niotor andA is.moreparticularlyivherein' 26 is the cylinder, 27 the piston',

and 28 the fixed abutment that en ages the hub 29 of the piston. Fluidis admitted and `exhausted from ports 30 and 31, as 'will apy 36.. gt

is' admitted by the. ipe 42 to the lports 43 ton1is free 'to' escape'through port 31 and ear later. The` piston of the motor is iieyed tothe cam shaft32, the `latter heilig best shown .in Fig. 2. Formeddirectly on the.shaft or secured thereon is a plurality of cams 33,which are adapted to actuate fthe high pressure nozzle valves by meansof the stems '134, Fig. 1. lFor thejfpurposes of description, thesecam's may be termed the main'.- cams'.4 The stems 34 are suitablypiclr'ed at 35 to prevent the escape of steam. The cam shaft issupported in ball bearings its ends and also at. intermediate points.'

A, Mounted on theileft-hand end of the. cam

shaft is a .pinion 3T-that meshes with a' rack 3.8,"'the latterbeingsuitably guided lin its movements by the walls of the/"casing 39.Theupper end of the rack'is pivotally con'- -ne'cted to the lever 24.'This lever is connectedby a pin with the stem 40 of the -balan'cedpilot valve 41. 'Fluid' under pressure situated between the ea'ds of thepilot valve.

The headsv o'f the valvenox'm'ally cover the .ports 44 and-.45 whichcommunicate .with

.the ports 30 and 31 ofthe motor, Fig. 7. Assume that the governor, dueto a decrease in speed of the turbine, moves the' pilot 'valve upward.This results' inopening the` port 44 and. ad1nitting high pressure fluidthereto and to the port 30, Fg.j 7, and to 4the upper side of thepiston-27. The piston thenmoves in the direction indicated bythe arrow.The same movement. of. the pilot valve o ns the'port 45,-a'nd the fluidcontained m the motor cylinder under the pis! i "port 45 into thepassage 46, the latter be- 45. 44 when the pilot valve' ismoveddownwa-rdly and the direction of-movement of g the lston 27'isopposite to thatindicatedv hy/tg I I Amg in constant communication withthe ex-` haust pipe 47. AThe passa e 46A also' servesto 'convey theexhaust fluir `from' the port earrow.A Referring-again tothe movement ofthe pilot' 'valve rstfreferred to, z'. e., moving upward. t'- expose-theport 44 to high pressure, .the cam shaftstarts into operation and' iwardly. Since the governor has moved the- Vin'so doing, turns vthe inion37. This move- -ment'is'communic'ate to'the jrack 3S, which under the'conditions described moves downs rodf22 to a position corresponding tothe speed of the turbine,the p1vot'48F1g. 4.

now becomes the fulcrum andthe pinion 3T :moves .the left-'hand end, of.the lever 24 downwardly by` an' amount suiigient to -rel.store the"cveri' .tie ports 44 and 45."Tl1is movemeut o` the cam shaftwillopenone' or more llot valve to its norma-l position of the nozzle valvesto agreater or less extent, .de ending upon the load thrown on the tur ine.Conversely, if the load decreases -and the speed .ot the turbineincreases, the .pilot valve moves in the opposite direction to'decreasethe number of opennozzle valves, and the pinion 3T' moves in the.opposite ,direction tores-tore the pilot -valve'. 41 to itsnormal-position, where it closes the ports leading to the motor.'

The mechanism for controllingr the admission of low pressure steam froman engine, accumulator, or .other sources will now be described: Mountedlon the right-hand' end of the .cam shaft 32 and located within thehousing is a cam 50 that has a cam groove 51, a portion of which isarranged 1n the form'ofa spiral, and another portion 52 is arranged in aplane perpendicular y to thev axis of the cam shaft.- For thepurpose ofthis description the 'cam' 50 may be termedA .the auxiliarycam.'l ThereasonI or this peculiar arrangement is that for certainspeed' changesthe low pressure valve only should-.move away from its seat-'nntl themaximum valve opening 'is reached, and' thereafter said low-pressurevalve should be' heldstat-ionary, while'the. cam shaftcon, -tinues'it'smovement to open the high pres. sure -nozzle 'valves one after theother. to admit high pressure steam, the latter being necessary when.the/supply of low-` pressure steam -is inadequate-' In orderto-transmit the movements of the spiral cam to=-the low pressure valvean' arm '53, Fig. 2, isl pro-4 vided, having at its lower end a` pm orroller 54 that makes a snug fit with-the Walls of the groove of thespira] cam. The upper end of the arm is mounted oii fa' rock-'shaft Tothis rock shaft is also.' attached a'rm bell-crank lever.' The outervend of the arm ,56 is connected byan adjustable connectingrod withV thebalanced low pressure. double vseated valve '5.8, the latter being'mounted upon the stem 59.. The stem 'is provided with a long bearingsurface to prevent the entrance of air or the escape of steam. The valveis provided with seats 60 and 61 that. are engaged by the upper andllower heads of the'valve.' As the speed of Vi'oxi '56'. -F ig. 1, saidarms 53 and 5(5 f6rming'a the turbine changes,due to changes in theload, valve 58 rises and falls in accordancelonger suficient to satisfytherequirements,

the. high pressure' valves begin- -to open. one

'with ythe amplitude -of-'the changes ot the speed andload, therebyhrottling the low pressure steam from the conduit 16 to va ,las

I "afteranoth'er until a balance effected betiveenth'e load requirementsand thel admission ofhlgh andlow pressure steam.

lln a governing ni'echanism of this ki'nd.'it

isf essential to provide meansl for shutting vdownl the turbine when torany reason' its act on the latch Fig'. 1. which latch engages 'ashoulder -on the. rod' (32%.' The right-hand end vof' the rod providedwith alfork'ed arm G4 that is mounted on a rock shaft (35. ythc latterbeing "supported by'a bracket from the 'main bearing of the turbine. Ontheleftflia-ndend of' rod- 63 is a handle GG.' so that it can berotated.. to free the shoulder from engagement with the llatcliT'VZ. Onthe roclrleliaftf is also mounted vertical rod (5S with vthe valve lever.69. The said arms'64 and 67 and shaft form fa bell-crank lever.

ofthe. high pressure emergency 'valve 72.

Between the lever 69 ano the spinoie 71 is av lcertain"tn nount off'lost motion, so'that 'a lnrmmerblow willlvbe imparted to thevalve vforthe purpose of startingit in the closing direction. Mounted on theverticalrod G8 is Van emergency motor. in this case ayveight .73,.thatutends at 'all times to close the.

.emergency valve. which tendency is 4resisted by.. the latch G21 etlectsof .thesho'ek due tothe falling weight when the. .latch 69. isv releaseda compresfsion spring 74 isprovided thatuests at one 'and moving the rod(i3 to a ,end on a shoulder on the rod (58 and the other fend engagesiveiglit.` This iveight is. intended to be resetjhyh-and. i; r. raisingthe rod (3S, weight. 3,lturn1ngarm (7..roek shaft (i5. arm4 G4,

the'. ,latch (Si). 'will engage the right by a spring. v The lowpressure .emergency-mechanism be described :4 Mounted on'the rockvshaftis an' arm'. located .directly backlof connected toa horizontal rod75.'. The. outerv endof this-rod is'slotted' 'to receive lthe lock.-

is 'providedon' the lever,'whereby'theklatter lever 76.

anal-111167 which is connect-ed by a The right-hand end of y the valvelever AG9 is supported 'by a link` and' attached to said lever isthe-stem 71' ln order to decrear'se the may be actuated by hand ifdesired. lnthc4 sliding;r and swinging bar is a slot S0 to receive a pincarried by the arm 81, the latter beingr rigidly secured to .the spindle82 of the l'mtterfly valveS-B.' On' the lower end of the bar 77- is anemergency'weight; '84, which normally tends to 'close the valve andwhich 'is prevented from so doing byithe locking The bar 77 is made intwo parts, an upper and lower7 which are connected by the pivot thatalso forms a handle, Fig. The weight. H4 is spring-supported in the samemanner and for the same reason as Weight 7?). Owingr to the fact. thatthere is a .pin and slot connection between the sliding and swinging bar77' and the 'arm S41, when the weight 84 is released. it. will -inipart'a hammer" blow to the butterfly valve and cause. the same to start fromits position ot" rest and close promptly'.

In Fig. 5' and Fig. 6' the details o'f the locking lever 76 are moreclearly. illustrated. `The Alever 7G is connected at itsright--hand a.lost-motion connection. The reason for providing the slot is to permitof resetting',r t'he bar 77 bythe handle S5, ,and also the valve 83withoutbeingoblged tofactuate lthe rod 75 or any of the parts beyondit.. 'In other v'vords` the weight 73 is reset. by one operation, Weight84 by another operation,-

.one .Weight is to be moved at a time. Saidpin and slot'connection alsoinsures a. hammer lolo'v'sr for starting the parts into opera-- tion.The :locking lever 76 normally held in the position shown in-Fig. 5. bythe spring 87 that isflocated'within the slot. in [Which .the left-handend of the lever moves.

In the event of'an emergency condition, and assuming` thattheemergencyugovernor. releases the latch 62, Vthe -weight 73 in fallingcloses the high pressure -valve 'and also :moves the' rod. 75, which inturn moves the locking. .lever 76 in the .direction to' release theemerf' the'fxvalled recess vin the' position where 4 shoulder of the'...rod.. l'I he rod (3.is normally moved to the I gency Weighty S4, thatAactuates' the-butterflyl valve 83.

It' is to be noted that. Weights or motons are provided for each o fcontrol ott-he weight. 73, and that both `Weights Yare controlled.by-the same einen gency governor. In "order to restore'. the.

'parts into position after the emergency op# eration. the butterflyvalve is first: restored by raisingthe weight. 84 and peri'iiitng'tlie.locking lever 7.6 to snap into `place: Vthen the high pressure emergencyvalve' is restored -raising the Iweilgrhi; 4latch (32 to engage -thfeshoulder in' the rod 63.'

-and then Vthe high; but under cert-ain condi` .tionsthis order -inay bereyersed.

the valvesthev ,ive-ight Slis under the direct.;

I prefer 'to restore first thef-lowp1ess11'1e.\alve' end by a pin andslot with the rod 75' to form which operations' are independent, sothat'v ioo whereas 'independent i .73j4 and permitting" the mechanismwhich is exceedinglysimple and =reliable operation.' Thefparts are verycompact and relatively4 small. Each pai-t is so located tha .t.it isentirely accessibleand one part can be `adjustedor removed without`disturbing the whole' mechanism. I anialsoableto a'void.- lost motioninA those. parts whereit Would bev an undesirable factor.A

The joints between the arts are'of the sirnples't character, .and thecaring surfacesamlple to prevent excessive Wear or strain.

-Byjarran 'ng'the weights 7.3'and 84 as de- I o tamthe great'advaiitagethat the -governor'latcli '62 only has to support one` of...the in.VWhen' 4the weight '73 isfreleased 'it, .not", only 'closes its ownvalve, but, supplies 4the necessary force' to trip the locking'device ofthe-second weight 84. This. i .insures prompt, action 'of both emergencyvalvesj '.with a.' relatively .small load on the 'emergency overnor, so.that the latter will operatie wi certainty at exactlylthe'predetrippingspeed;

In. accordance with tlij provisionsfo'f the patent'-A statutes, 1 havedescribed the tprinciple of operation Aof my -invention,. together Atheinvention can be carried out' by other'.V

the admission of loiv pressure' tiuic 1 turbine', aniotor for actuatingboth of said valve means, -a speed governor' that 'controlswiththe-'apparatus which I no i'v consider to paratis fSliOwn is onlyillustrative and 4that What I4 by Letters .Patent of the United States,is-

1.A turbine having -afconduitforsup-n plyin high4 pressure niot'iveiiuid'aiid a conduit vorsupplying low pressure motive fluid,

-.in.conibination with a. valve meansfor regu.Y

-lating the admission of high pressure iuid to the turbine, valve' meansffor regulating said valve means vandis driven by the tur- "isi,

bine,'emergency valves-'independent in action of said'regulating valves,independent motors for 'operating the emergency valves',

A4latchesfor revent'ing' both motors fr oni operatii'ig an a speedgovernor, 'also dri'ven by the 'tu"bine, that trips one-'latijn theother A being tripped'by one of the motors.

' supplying 2.LA turbine iaving av conduit. for supplying high 'prssurefluid. und a Aconduit for low pressure motive huid, in. combination1with valves'for regulating. thc acl- 'missionfof high pressure fluid tolthe tur."

bine,v ac'am shaft for moving the valves, a

"motor mounted on one'cnd of the shaftfor actuating it, a low' pressurevalve- 'nieclia-- nism, a' bell-crank leverandi-cd for trans.-l'nitt-ingniotion from Vthe ca ui' shaftj, to the .lowf pressure lvalvemechanism, emergency yvalv'esforthe high and-low pressure. sourcesthat are 'ar ranged. t-o close independently 'ofl re Vresent theembodiment thereof "but I have it understood that' the :ip-

to the'- .evenos the regulating valves, and an emergency 4governor thatcontrols the emergencyvalves.

3.. A turbine having a conduit. for supplybiiiation with valve nieansfor regulating the admission .of lh1 'h pressure fluid to-the a in otormounted on' vthe shaft for' actuating Vit directly, a low'pressure valvemechanism,

`an rod actuated by the-spiral' cam for movmg the low pressure valvemechanisnn. a

gencv val-ve,- a sliding and.swinginvr rod` a weigl'iton the rodforclosing the va ve, and means' foi-'releasing thea-od and'iveight..

4. A turbine having high and-'lowpressure supply conduits, a v alve foreach of the a motorl mounted 'directly on -th e', shaft-r. f or movingit, a governor or controlling' the 1 ently -of'the regulating valve', ameans for imparting a ,hammer blow to said- 4valve to 'releas'in said"atcli.

' -5. ti rb'ne having high and low pressurev supply co duits, aplurality of high ressure valve's, a low pressure' valve,said va ves actcams for .actuating the'. high pressure'valves successively, 'anauxiliary cam which pre- 'cedesntlie in in. 'ca 'mfin its operationunder conditions ci i creasing load on the turbine,` ashaft for th'camsg a.powertransmittin' the low pressure va'l've, a motor mounteddirectly on' the shaft that drives Iall of the ca'ins,- a sped-igovernor forcontrolling the motor, a lov -slidin -rod'or actuatingit, a locking lever. theieor,lnieans tending to hold the .locling "a s'4iral cam driven bv the 'c'am shaft, a lever governor for the -i'notor,'abuttertiy enier vclose it suddenly,'a restraining-'latch foi-:said`means, and a' ove'rno'i" controlledf motor for' U connection between theauxiliary cam and .pi'essure' emergency valve, a'

lever inenga ement. with the' rod, and means lt e lever againsttli'e-acticiiiof ves .regulatingtlicfsupply of fluid4 sure .valve or'valves start'iiito operation uning high. pressure.4 fluid and a conduit.foi' supplying loiv pressure 'motive fiuid, incomturbine, a cam lshaft.for actuating thevalves,

'1notor, means actuated 4by. tliehcamthat is gencyl low g pressurevalveactingv independin g' on the supplies from the conduits,maindeico'nditions lof' increasing load, andreas- Ato a`ii 'd, drivesall of 'the cams, a governorcontrolled means .for regulating l'theaction tfof the motor, 'high and' .sume its'ivork after thehigh pressure'valve or valves are closed, a motor'that is common,

gency valves, a closing 'weight tor each valve, means actuated by oneweight for releasing the other, and a governor for conti'olling theaction ot' said weights.

T. A turbine having high and low pressure supply conduits, high and lowpres- -sure regulating valves, means for actuating them, high and lou'pressure emergency valves, means for actuating them, and a sing'leemergency governor. that controls, the closing of both emergency valves.

8. A turbine having high and low pressure supply conduits, high and lowpressure regulating valves, `means for actuating them, high and lowpressure emergency valves, a'motor for each emergency valve for closinit, an emergency governor, means actuated )y the governor for releasingone of said motors, and a device actuated by'one motor for releasing theother.

SLA turbine havinghigh and low pressure supply conduits, high and lowpres-A sure regulating calves, high and low pressu're emergency valves,motors tor actuating them that tendat all times to move thevalves, agovernor controlled latch that 'preventsI one of the. motorsfromoperating. a

governor forreleasin'g said latch which is responsive to an al'mormalcondition of op?.

eration. and a lostanotion device operated lh v..tv|;\e til-st motor forreleasing the second.

lt). A turbine having high and low pressure supply conduits, vhigh andlow pressure regulating valves, high and loiv pres sure emergency valvestherefor, a means for holding the high pressure emergency valve in itsopen position, a means for holding 'the lovv pressure emergency valve inits -open said device.

close the en'rergency valves, a locking device' for the motors,

and a -governor foractuaf ing sure supply conduits, high and low pres`sure ,emergency valves therefor, a motor for actuating the high pressurevalve, a motor for actuating the low .pressure valve, a lock restrainingthe low pressure valve from operating, a `power transmitting agentbetween the motor that operates the high pressurel valve ,and the lock,and a lost-motion device insaid agent. i

13'. In a governor mechanism, the combination .of a motor, a-shatt'-drivtn thereby, a. pilot valve ior controlling.,r the movementsof the motor piston, a governor, a .lever that is attached to the pilotlvalve and is vmoved by t'he governor. and a follow-up device .'for thepilot valve comprising a pinion driven by the motor` and afrack meshingtherewith which is attached toithe lever andauider certain conditionsholds one end ot' the lever stationary and at other times moves it.

, In witness whereof, I have hereunto set my hand this 10th day of)'Iarch,15)10.l

FREDERIC-K SAIUELSOX.

BENJAMIN B. HULL, HELEN ORFORD.

